WO2018055963A1

WO2018055963A1 - Projection lens and projector

Info

Publication number: WO2018055963A1
Application number: PCT/JP2017/029920
Authority: WO
Inventors: 泰斗黒田
Original assignee: 富士フイルム株式会社
Priority date: 2016-09-23
Filing date: 2017-08-22
Publication date: 2018-03-29
Also published as: CN109791347B; JP2020106858A; JP6905116B2; CN109791347A; US20190219802A1; US20210247598A1; JP6670388B2; JPWO2018055963A1

Abstract

Provided are a projection lens and a projector that can project the center of the screen to a side reverse of the normal orientation to the optical axis of the projection lens without disposing a projector main body upside down. A projection lens (10) is divided by a second mirror (14) into a first optical system (11) disposed on an image forming panel (67) side and a second optical system (12) that includes a mirror (14) and is disposed on a side for a screen (28), which is a projection surface. The second optical system (12) is inverted 180° with respect to the first optical system (11) around a second optical axis (CL2) by an inverting unit (17) and set to a first position and a second position. An image displayed on the image forming panel (67) is inverted in correspondence with the first position and second position and the orientation of a projected image on the screen (28) is set for the first position and the second position. Projection wherein the center of the screen is positioned on the upper side or the lower side of the optical axis is possible by switching to the first position or the second position.

Description

Projection lens and projector

The present invention relates to a projection lens and a projector.

In recent years, projectors equipped with an image forming panel such as a liquid crystal display element or DMD (Digital Micromirror Device) have become widespread and have high performance.

Patent Document 1 describes a liquid crystal projector that irradiates light from a light source onto a transmissive liquid crystal panel and enlarges and projects an image displayed on the liquid crystal panel through a projection lens onto a screen surface. The liquid crystal projector of Patent Document 1 has a reflecting member having a reflecting surface that reflects image light including a projected image incident on a projection optical system that projects an image, and the tilt angle of the reflecting surface with respect to the image light can be changed. I have to. Thereby, it is possible to easily adjust the position of the projection surface on which the image is projected.

In addition, the liquid crystal projector of Patent Document 2 selectively disposes a mirror tilted at 45 ° with respect to the optical axis in front of the projection lens, so that an optical image emitted from the projection lens can be obtained without changing the main body position of the liquid crystal projector. Projection is possible in the horizontal and vertical directions.

JP 2007-264554 A JP 2009-210702 A

When the projector does not have a lens shift function, when the projector main body is in the normal orientation, the projector projects the optical axis of the projection lens so that the image projected on the screen is positioned above the projector. In general, the center of the screen is projected on the upper side. Therefore, when it is desired to project the center of the screen below the optical axis of the projection lens, it is necessary to arrange the projector body upside down.

In addition, even if the projection direction is switched using a reflecting member as in

Patent Documents

1 and 2, if it is desired to project the center of the screen below the optical axis of the projection lens, similarly, It is necessary to reverse the arrangement.

However, in order to place the projector body upside down, a dedicated ceiling suspension is required. Further, the projector main body often has operation switches on the upper surface. Therefore, when the projector is used with the top and bottom of the projector body arranged upside down, the operation switches turn downward, making operation difficult.

The present invention has been made in view of the above circumstances, and is a projection lens capable of projecting the center of the screen in the direction opposite to the normal direction with respect to the optical axis of the projection lens without arranging the projector body upside down. And a projector.

In order to achieve the above object, a projection lens of the present invention projects an image of an image forming panel onto a projection surface, and shifts one of the image forming panel and the projection lens in a direction perpendicular to the optical axis. Used for projectors. The projection lens includes a mirror that bends the optical axis, a first optical system, a second optical system, and a reversing unit. The first optical system is disposed on the image forming panel side with respect to the mirror. The second optical system includes a mirror and is disposed on the projection surface side. The reversing unit selectively holds the second optical system around the optical axis with respect to the first optical system at a first position and a second position that is 180 ° reversed from the first position.

There are a plurality of mirrors, and the mirror that separates the first optical system and the second optical system is preferably an outermost-side mirror disposed on the optical axis closest to the projection surface.

The reversing unit preferably includes a sensor that detects the first position and the second position. The reversing unit preferably has a position index for displaying the first position and the second position. The reversing unit is preferably switched to the first position and the second position by rotating the second optical system around the optical axis with respect to the first optical system. The reversing unit preferably has a click mechanism for fixing the second optical system at the first position and the second position.

Moreover, it is preferable to have a light shielding part. The light blocking unit blocks the light from the image forming panel when the second optical system is not disposed at any of the first position and the second position and the sensor is in an undetected state where the sensor is turned off.

A projector according to the present invention includes the projection lens, an image forming panel that displays an image, a light source that illuminates the image forming panel, a housing, and an image display reversing unit. The housing accommodates one of the image forming panel and the projection lens shifted in a direction perpendicular to the optical axis. The image display reversing unit interlocks with the switching of the second optical system to the first position or the second position, and adjusts the direction of the projected image on the projection surface based on the sensor signal to match the direction of the projected image at the first position and the second position. Invert.

In addition, it is preferable to have a light shielding part. The light blocking unit blocks the light from the image forming panel when the second optical system is not disposed at any of the first position and the second position and the sensor is in an undetected state where the sensor is turned off. The light shielding unit may be provided in the projection lens or between the projection lens and the image forming panel. The projection lens is preferably detachably attached to the housing.

According to the present invention, it is possible to provide a projection lens and a projector that can project the center of the screen in the direction opposite to the normal direction with respect to the optical axis of the projection lens without arranging the projector body upside down. it can.

It is a perspective view which shows the projector of this invention. It is a longitudinal cross-sectional view of a projector. FIG. 3 is a cross-sectional view of an essential part taken along line III-III in FIG. 2 showing an inversion part. It is a longitudinal cross-sectional view which shows the back launch projection in the back projection position which is a 1st position. It is a longitudinal cross-sectional view which shows the front-down projection in the front projection position which is a 2nd position. It is sectional drawing of the principal part which shows a click mechanism. It is a flowchart which shows the procedure of the image display inversion control in a control part, and the control of a light-shielding part. It is a top view which shows the projector of 2nd Embodiment using one mirror. It is a side view of the projector of 2nd Embodiment. It is a front view of the projector of 2nd Embodiment in a 1st position. It is a front view of the projector of 2nd Embodiment in a 2nd position. It is sectional drawing of the principal part of 3rd Embodiment of the state switched to the 1st position by fitting. It is sectional drawing of the principal part of 3rd Embodiment of the state switched to the 2nd position by fitting. It is a top view of the principal part which shows a reference | standard parameter | index and a position parameter | index.

[First Embodiment]
As shown in FIG. 1, the projector 2 of the present embodiment includes a projection lens 10 and a projector main body 60. FIG. 1 shows a case where the projector 2 is arranged on a horizontal surface such as a table.

As shown in FIG. 2, the projection lens 10 includes a first optical system 11, a second optical system 12, a first mirror 13, a second mirror 14, a first holding member 15, and a second holding member 16. And a reversing unit 17. The first holding member 15, the second holding member 16, and the reversing unit 17 constitute a lens barrel 18.

The first optical system 11 includes a first lens 21, a second lens 22, a third lens 23, a fourth lens 24, and a first mirror 13. The first lens 21, the second lens 22, and the fourth lens 24 are displayed as single lenses for the sake of simplicity of illustration, but are actually configured by a plurality of lens groups. The first lens 21 and the second lens 22 form the illumination light from the image forming panel 67 on the imaging surface 27 as an intermediate image.

The first mirror 13 is disposed between the second lens 22 and the third lens 23. The first mirror 13 bends the first optical axis CL1 of the first lens 21 and the second lens 22 by reflection to form a second optical axis CL2 that intersects the first optical axis CL1 at 90 °.

The first holding member 15 includes a first main body 30, a first lens frame 31, a first mounting cylinder 32, a second mounting cylinder 33, and a third mounting cylinder 34. The first holding member 15 integrally holds the first lens 21 to the fourth lens 24 and the first mirror 13. The 1st main body 30 is comprised from the substantially rectangular parallelepiped square tube. One corner of the lower plate 30a of the first main body 30 is cut obliquely to form a slope 30b. The first mirror 13 is fixed to the inner side surface of the slope portion 30b.

A first mounting hole 30d of the first optical system 11 is formed in the front plate 30c on the entrance side facing the slope portion 30b. One end of the second mounting cylinder 33 is fixed to the first mounting hole 30d. A second mounting hole 30 f is formed in the upper plate 30 e of the first main body 30. The lower end portion of the third mounting cylinder 34 is fixed to the second mounting hole 30f. The third mounting cylinder 34 holds the third lens 23 and the fourth lens 24 along the second optical axis CL2.

The second optical system 12 includes a second mirror 14, a fifth lens 25, and a sixth lens 26. The second mirror 14 is disposed between the fourth lens 24 and the fifth lens 25. The second mirror 14 bends the second optical axis CL2 by reflection to form a third optical axis CL3 that intersects the second optical axis CL2 at 90 °. Although the fifth lens 25 and the sixth lens 26 are displayed as single lenses for the sake of simplicity of illustration, they are actually composed of a plurality of lens groups. The third lens 23 to the sixth lens 26 magnify and project the intermediate image formed on the image plane 27 by the first lens 21 and the second lens 22 onto a projection target, for example, the screen 28.

The second holding member 16 includes a second main body 40, a second lens frame 42, and a third lens frame 43. The second holding member 16 holds the fifth lens 25, the sixth lens 26, and the second mirror 14 together. The 2nd main body 40 is comprised from the substantially rectangular parallelepiped square tube. One corner of the upper plate 40a of the second body 40 is cut obliquely to form a slope 40b. The second mirror 14 is fixed to the inner side surface of the slope portion 40b.

A mounting flange 40c is formed on the end surface of the second body 40 that faces the inclined surface 40b in the horizontal direction. A third lens frame 43 is fixed to the mounting flange 40c. A second lens frame 42 is attached to one end of the third lens frame 43 so as to be movable in the direction of the third optical axis CL3. The fifth lens 25 is fixed to the second lens frame 42, and the sixth lens 26 is fixed to the third lens frame 43. The second lens frame 42 is moved along the third optical axis CL3 by a lens moving mechanism (not shown) to adjust the focus.

The lens configurations of the first lens 21 to the sixth lens 26 are described in detail in “Projection optical system and projection display device” in, for example, Japanese Patent Application Nos. 2015-035085 and 2015-045589. The described optical system can be used as the first optical system 11 and the second optical system 12. According to these projection optical systems and projection display devices, it is possible to obtain an optical system having high projection performance in which various aberrations are well corrected at a wide angle.

In the present embodiment, the first optical axis CL1 of the first lens 21 and the second lens 22 is reflected by the first mirror 13 and bent at 90 ° to become the second optical axis CL2. The second optical axis CL2 of the third lens 23 and the fourth lens 24 is reflected by the second mirror 14 and bent at 90 ° to become the third optical axis CL3 on the emission side. The third optical axis CL3 is parallel to the first optical axis CL1 in a plane including the first optical axis CL1 and the second optical axis CL2.

The inversion portion 17 is disposed between the upper end portion of the third mounting cylinder 34 and the lower plate 40d of the second body 40. The reversing unit 17 includes a first flange 45, a second flange 46, a circumferential groove 47, a guide pin 48, a first sensor 49, and a second sensor 50. The first flange 45 is formed in a disc shape on the outer peripheral surface of the upper end portion of the third mounting cylinder 34. The second flange 46 is formed in a disc shape on the lower plate 40 d of the second main body 40.

As shown in FIG. 3, the circumferential groove 47 is a semicircular groove centered on the second optical axis CL 2 and is formed on the lower surface of the second flange 46. As shown in FIG. 2, the guide pin 48 is provided in parallel with the second optical axis CL2 so as to protrude from the upper surface of the first flange 45. In a state where the first flange 45 and the second flange 46 are combined, the tip of the guide pin 48 enters the circumferential groove 47. As shown in FIG. 3, the circumferential groove 47 is formed in an angle range of 180 ° with the second optical axis CL2 as the center. Therefore, the guide pin 48 guided by the circumferential groove 47 can move within the length range of the circumferential groove 47. As a result, the second optical system 12 having the second main body 40 is allowed to rotate at an angle of 180 ° with respect to the first optical system 11 having the third mounting cylinder 34 and can be reversed.

As shown in FIG. 3, when the guide pin 48 is positioned at one end of the circumferential groove 47, as shown in FIG. 4, the rear projection position (the sixth lens 26 of the second optical system 12 faces the back) ( Corresponding to the first position). At the rear projection position, the second optical system 12 projects an image toward the rear. Then, the image shown on the screen 28 is projected above the third optical axis CL3 to form a so-called launch projection.

On the other hand, when the second optical system 12 is turned 180 ° from the rear projection position and the guide pin 48 is positioned at the other end of the circumferential groove 47, as shown in FIG. The front projection position (corresponding to the second position) in which the six lenses 26 face the front is obtained. At the front projection position, the second optical system 12 projects an image toward the front. Then, the image shown on the screen 28 is projected below the third optical axis CL3, which is a so-called down projection.

2 and 3, a first sensor 49 and a second sensor 50 are attached to the first flange 45 in order to detect the orientation of the second optical system 12. For example, a photo interrupter is used for the first sensor 49 and the second sensor 50. An L-shaped sensor plate 57 protruding in the radial direction is attached to the outer peripheral surface of the second flange 46. When the sensor plate 57 blocks the detection light of the first sensor 49 or the second sensor 50, the first sensor 49 and the second sensor 50 are turned on. When the first sensor 49 is turned on, it is detected that the second optical system 12 is set at the rear projection position. When the second sensor 50 is turned on, it is detected that the second optical system 12 is set at the front projection position. On the other hand, when the second optical system 12 is not disposed at any position of the rear projection position and the front projection position, the first sensor 49 and the second sensor 50 are turned off. Hereinafter, this state is referred to as a non-detection state.

The signals of the first sensor 49 and the second sensor 50 are sent to the control unit 69 of the projector main body 60 via the mount unit 61 described later. Since the

sensors

49 and 50 are attached to the first flange 45 that is the fixed side at the time of reversal, the wiring to the

sensors

49 and 50 is less than when the

sensors

49 and 50 are attached to the second flange 46. It becomes easy.

As shown in FIG. 6, a click mechanism 51 is provided on the mating surface of the first flange 45 and the second flange 46. The click mechanism 51 includes a locking hole 52, a locking ball 53, a coil spring 54, and a spring holding screw 55, and positions the second optical system 12 at the rear projection position and the front projection position. The locking hole 52 is formed of a spherical recess, and is formed at a position corresponding to the rear projection position and the front projection position on the mating surface of the first flange 45, for example. The spring holding screw 55 is screwed into the locking ball storage hole 56 to hold the locking ball 53 and the coil spring 54 in the locking ball storage hole 56. The locking ball 53 is biased by the coil spring 54 so as to come into contact with the mating surface of the first flange 45.

The first holding member 15 and the second holding member 16 are assembled individually. As shown in FIG. 2, the second optical axis CL 2 on the emission side of the first optical system 11 and the second optical axis CL 2 on the incident side of the second optical system 12 are aligned with each other through the inverting unit 17. Then, the first holding member 15 and the second holding member 16 are joined to assemble the lens barrel 18. In the lens barrel 18 assembled in this way, the second optical axis CL2 and the first optical axis CL1 on the incident side of the first optical system 11 having an angle of 90 ° with respect to the second optical axis CL2. A U-shaped optical path is formed by the third optical axis CL3 on the emission side of the second optical system 12.

As shown in FIG. 1, the projection lens 10 is detachably attached to the projector main body 60 via the mount portion 61. The projector main body 60 has a housing 65 having a substantially rectangular parallelepiped shape. In the housing 65, a light source 66, an image forming panel 67, a light shielding unit 68, and a control unit 69 are accommodated.

For example, a transmissive liquid crystal panel is used as the image forming panel 67. The light source 66 is disposed on the back surface of the image forming panel 67, that is, on the opposite side of the projection lens 10 with respect to the image forming panel 67. The light source 66 uses LEDs (light-emitting diodes) that simultaneously emit three colors of red (R), green (G), and blue (B), and illuminates the image forming panel 67. Note that a xenon lamp, a halogen lamp, or an ultrahigh pressure mercury lamp that emits white light may be used instead of the LED. The projection lens 10 projects illumination light from the image forming panel 67 illuminated by the light source 66 onto a projection surface such as the screen 28.

The light shielding unit 68 is disposed, for example, between the image forming panel 67 and the first lens 21. The light shielding unit 68 may be a mechanical shutter that opens and closes a shutter, or a unit that selectively inserts an ND filter into the optical path. The light shielding unit 68 switches between a light shielding state where the projection light from the image forming panel 67 is blocked and a passage state where the light is allowed to pass through. 2, the light shielding unit 68 may be provided on the projection lens 10 side instead of being provided on the projector main body 60 side.

The control unit 69 turns on the light source 66 and displays an RGB three-color image on the image forming surface 67a which is the surface of the image forming panel 67 opposite to the surface facing the light source 68. Further, the control unit 69 has an image display reversing unit 69a. The image display reversing unit 69a performs reversal control of the image based on the stop position signal of the second optical system 12 from the

sensors

49 and 50. When the first sensor 49 is ON and the second optical system 12 is at the rear projection position and is in the rear launch projection state, a normal image (upright image) is displayed on the image forming panel 67. Further, when the second optical system 12 is in the front projection position and in the front down projection state, an inverted image (inverted image) obtained by inverting the image upside down is displayed on the image forming panel 67.

In the non-detection state in which the first sensor 49 and the second sensor 50 are OFF, the control unit 69 does not place the second optical system 12 at either the rear projection position or the front projection position. 68 is operated to block the projection light from the image forming panel 67. On the other hand, the control unit 69 activates the light shielding unit 68 in a state other than the non-detection state, and makes the projection light from the image forming panel 67 pass.

FIG. 7 is a flowchart showing a procedure of image display inversion control and control of the light shielding unit 68 in the control unit 69 based on the signals of the first sensor 49 and the second sensor 50. When the first sensor 49 is ON (Y in step ST100, when the second optical system 12 is arranged at the rear projection position which is the first position), the control unit 69 operates the light shielding unit 68, The projection light from the image forming panel 67 is set in a passing state (step ST110), and the image display reversing unit 69a is controlled to display an erect image (step ST120). Thereby, as shown in FIG. 4, an image is projected on the screen 28 above the third optical axis CL3, which is a so-called launch projection.

On the other hand, when the second sensor 50 is ON (Y in step ST130, when the second optical system 12 is disposed at the front projection position which is the second position), the control unit 69 blocks light as in step ST110. The unit 68 is operated to allow the projection light from the image forming panel 67 to pass (step ST140), and the image display reversing unit 69a is controlled to display an inverted image (step ST150). As a result, as shown in FIG. 5, an image is projected onto the screen 28 below the third optical axis CL 3, which is a so-called down projection. As described above, the image display reversing unit 69a is interlocked with the switching of the second optical system 12 to the rear projection position or the front projection position, and the orientation of the projection image on the screen 28 should be adjusted at the rear projection position and the front projection position. The first sensor 49 and the second sensor 50 are switched based on signals.

When the first sensor 49 and the second sensor 50 are OFF, that is, in the non-detection state (N in both step ST100 and step ST130), the second optical system 12 is rotating. 68 is actuated to block the projection light from the image forming panel 67 (step ST160). In this state, since the projection light from the image forming panel 67 is blocked by the light shielding unit 68, no image is projected from the second optical system 12. Hereinafter, as long as the main switch is ON (N in step ST170), the above process is repeated. When the main switch is turned off (Y in step ST170), the above control is terminated.

The control unit 69 also performs the following processing. For example, when the electric zoom control function is incorporated in the projection lens 10, when the operation signal of the zoom dial 71 (see FIG. 1) is received, the size of the image projected on the screen 28 is adjusted. When the control unit 69 receives an operation signal from the focus dial 73 (see FIG. 1), the control unit 69 operates a focus adjustment mechanism (not shown) of the projection lens 10 to adjust the focus of the image projected on the screen 28.

As shown in FIG. 2 and the like, the image forming panel 67 is arranged to be shifted downward with respect to the first optical axis CL1, and for example, an image is displayed below the first optical axis CL1. On the other hand, the image projected through the first optical system 11 and the second optical system 12 is displayed on the screen 28 while being shifted above the third optical axis CL3. As a result, as shown in FIG. 4, at the rear projection position, the image is irradiated above the third optical axis CL 3 on the screen 28 arranged on the rear side.

When it is desired to project an image below the third optical axis CL3, the second optical system 12 is rotated (inverted) 180 ° around the second optical axis CL2 by holding the second main body 40. Thereby, as shown in FIG. 5, the sixth lens 26 faces the front side. In this state, due to the reflection by the second mirror 14, the image projected on the screen 28 becomes a down projection positioned below the third optical axis CL 3.

In this way, launch irradiation and down irradiation can be easily performed by a simple operation of rotating the second optical system 12 180 degrees around the second optical axis CL2 without turning the projector body 60 upside down. Can be switched. At the time of this switching, the image display reversing unit 69a flips the image displayed on the image forming panel 67 upside down. Therefore, the up-down direction of the image after switching is not reversed.

In addition, since the projection light is blocked by the light shielding unit 68 in the non-detection state in the middle of switching, the projection light is not projected from the rotating projection lens 10, and it is possible to eliminate the uncomfortable feeling during switching. Further, since the second optical system 12 is positioned at the rear projection position and the front projection position by the click mechanism 51, the second optical system 12 can be reliably reversed.

The reversing unit 17 may be any structure that can rotate the third mounting cylinder 34 and the second main body 40 about the second optical axis CL2 by 180 °, and various reversing guide mechanisms can be used. For example, a circumferential groove is formed on the outer circumferential surface of the third mounting cylinder 34, and a guide pin that enters the circumferential groove is provided on the inner circumferential surface of the mounting hole of the second body 40 to which the third mounting cylinder 34 is mounted. The second optical system 12 is reversed by restricting the movement of the guide pin. Although the second optical system 12 is reversed manually, a rotating gear may be provided integrally with the second flange 46, and the rotating gear may be rotated automatically by a motor. In this case, a switch for switching the position of the second optical system 12 by driving a motor in the housing 65 is provided.

[Second Embodiment]
In the first embodiment, two

mirrors

13 and 14 are used. However, in the second embodiment shown in FIGS. 8 to 11, the first mirror 13 is eliminated and only the second mirror 14 is used, and the optical axis is set to L. It has a letter shape. In the second embodiment, a cylindrical first main body 75 is provided in place of the first main body 30 of the first embodiment formed of a substantially rectangular parallelepiped square tube. The first main body 75 is accommodated in the projector main body 60. The second mirror 14 bends the first optical axis CL1 (not shown) of the first lens 21 and the second lens 22 to obtain a second optical axis CL2. The configuration is the same as that of the first embodiment except that the first mirror 13 of the first embodiment is eliminated and the first main body 75 is cylindrical. In the following embodiments, the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

In the second embodiment, the second optical system 12 can be rotated 180 ° with respect to the first optical system 11 by the reversing unit 17 using one mirror 14 as in the first embodiment. Therefore, as shown in FIG. 10, a launch projection that displays an image above the second optical axis CL2, and a down projection that displays an image below the second optical axis CL2, as shown in FIG. And become possible. In the second embodiment, the position of the second optical system 12 shown in FIG. 10 corresponds to the first position, and the position of the second optical system 12 shown in FIG. 11 corresponds to the second position. Also according to the second embodiment, the center of the screen can be projected on the side opposite to the normal direction with respect to the optical axis CL3 without arranging the projector body 60 upside down.

[Third Embodiment]
In the first and second embodiments, the reversing unit 17 that rotates the second optical system 12 is used in a state where the second optical system 12 is connected to the first optical system 11, but the first and second embodiments shown in FIGS. In 3 embodiment, the inversion part 80 by a fitting system is used. The reversing unit 80 has two key grooves 82 and one key protrusion 84. The key groove 82 is formed in parallel with the second optical axis CL2 at a position 180 degrees away from the first flange 81 of the first optical system 11 in the circumferential direction. The key protrusion 84 is a columnar protrusion extending in parallel with the second optical axis CL2. The key protrusion 84 protrudes downward from the lower surface of the second flange 83 formed on the second main body 40, and is disposed on the outer periphery of the third mounting cylinder 34.

When the second optical system 12 is assembled to the first optical system 11, the key projection 84 is inserted into one key groove 82 or the other key groove 82, so that the first optical system 12, as shown in FIGS. The fitting position of the second optical system 12 with respect to the system 11 can be switched. A key sensor 85 is attached to the third attachment cylinder 34 at a position corresponding to the key groove 82. The key sensor 85 is constituted by a limit switch, for example, and detects the key protrusion 84. The key sensor 85 can detect whether the second optical system 12 is in the first position or the second position. In the third embodiment, the position of the second optical system 12 shown in FIG. 12 corresponds to the first position, and the position of the second optical system 12 shown in FIG. 13 corresponds to the second position. Also according to the third embodiment, the center of the screen can be projected on the opposite side of the normal direction with respect to the optical axis CL3 without arranging the projector body 60 upside down.

In each of the above embodiments, one mirror 14 or two

mirrors

13 and 14 are used, but three or more mirrors may be used. In this case, the first optical system 11 and the second optical system 12 are separated by the outermost-side mirror disposed closest to the screen 28 that is the projection surface on the optical axis. Incidentally, the outermost mirror in the first embodiment is the second mirror 14.

In the first embodiment, the second optical system 12 is selectively stopped at the rear projection position that is the first position and the front projection position that is the second position by using the click mechanism 51. Alternatively or additionally, the second optical system 12 may be positioned at the first position and the second position using a reference index 90 and a position index 91 as shown in FIG. The reference index 90 is formed on the outer peripheral edge of the upper surface of the second flange 89 formed on the second main body 40. The second flange 89 has a smaller outer diameter than the second flange 46 of the first embodiment. Thereby, the outer peripheral edge of the first flange 45 is exposed from the outer peripheral edge of the second flange 89 in plan view. A position index 91 is formed on the exposed upper surface of the outer peripheral edge of the first flange 45. The position index 91 is connected to the reference index 90 in a straight line when the position index 91 reaches the first position and the second position. Accordingly, by rotating the second optical system 12 and aligning the position index 91 with the reference index 90, the second optical system 12 is selectively positioned at the first position and the second position with respect to the first optical system 11. can do.

In each of the above embodiments, a transmissive liquid crystal panel is used as the image forming panel 67, but a reflective liquid crystal panel may be used. In this case, a light source 66 is disposed on the front side of the image forming panel 67 and irradiates three colors of RGB simultaneously. When a DMD is used as the image forming panel 67, the light source 66 is disposed on the front side of the image forming panel 67, and the RGB three-color LEDs are caused to emit light in a time-sharing manner in synchronization with the DMD three-color image formation timing. .

In each of the above embodiments, the projector 2 is described as being arranged on a table. However, the present invention can also be applied when the projector 2 is suspended from a ceiling or the like. Moreover, although the example which projects an image on the screen 28 demonstrated, the projection surface is not limited to the screen 28, It can use as a projector which projects with respect to various projection surfaces.

In each of the above embodiments, terms such as orthogonal and parallel are used to represent the positional relationship between a plurality of optical axes, or a specific numerical angle such as 90 ° is used for explanation. However, these include a range that is allowed with an error corresponding to the accuracy required in the optical system.

In the first embodiment, the projector 2 in which the projection lens 10 is replaceable via the mount 61 has been described. However, the projector 2 can be applied to a projector in which the projection lens 10 is fixed to the projector main body 60. When the projection lens 10 is replaceable, for example, a part of the first optical system 11, for example, the first lens 21 and the second lens 22 are provided in the projector main body, and the number of lenses on the projection lens 10 side. May be reduced.

In the first embodiment, the image forming panel 67 is shifted downward with respect to the first optical axis CL1, but may instead be shifted upward. Further, the object to be shifted in the direction orthogonal to the first optical axis CL1 may be the projection lens 10 instead of the image forming panel 67. Furthermore, both the image forming panel 67 and the projection lens 10 may be shifted and arranged. Good.

2 projector 10 projection lens 11 first optical system 12 second optical system 13 first mirror 14 second mirror 15 first holding member 16 second holding member 17 reversing part 18 lens barrel 21 first lens 22 second lens 23 first 3 lens 24 4th lens 25 5th lens 26 6th lens 27 Imaging surface 28 Screen 30 1st main body

30a Lower plate 30b Slope

30c Front plate 30d 1st mounting hole 30e Upper plate 30f 2nd mounting hole 31 1st lens Frame 32 First mounting cylinder 33 Second mounting cylinder 34 Third mounting cylinder 40 Second body 40a Upper plate 40b Slope 42 Second lens frame 43 Third lens frame 45 First flange 46 Second flange 47 Circumferential groove 48 Guide pin 49 First sensor 50 Second sensor 51 Click mechanism 52 Locking hole 53 Locking ball 54 Coil spring 55 Spring retainer 56 Locking ball storage hole 57 Sensor plate 60 Projector body 61 Mount portion 65 Housing 66 Light source 67 Image forming panel 67a Image forming surface 68 Light shielding portion 69 Control portion 69a Image display reversing portion 71 Zoom dial 73 Focus dial 75 First body 80 reversing portion 81 first flange 82 key groove 83 second flange 84 key protrusion 85 key sensor 89 second flange 90 reference index 91 position index CL1 first optical axis CL2 second optical axis CL3 third optical axis ST100 to ST170 Steps

Claims

In a projection lens that projects an image of an image forming panel onto a projection surface, and is used in a projector that is arranged by shifting one of the image forming panel and the projection lens in a direction perpendicular to the optical axis,
A mirror that bends the optical axis;
A first optical system disposed on the image forming panel side with respect to the mirror;
A second optical system including the mirror and disposed on the projection surface side;
A projection lens comprising: a reversing unit that selectively holds the second optical system around the optical axis with respect to the first optical system at a first position and a second position that is reversed by 180 ° from the first position.
The plurality of mirrors are provided, and the mirror that separates the first optical system and the second optical system is the outermost-side mirror disposed on the optical axis and closest to the projection surface. 1. The projection lens according to 1.
3. The projection lens according to claim 1, wherein the reversing unit includes a sensor that detects the first position and the second position.
4. The projection lens according to claim 3, wherein the reversing unit has a position index for displaying the first position and the second position.
5. The projection lens according to claim 3, wherein the reversing unit rotates the second optical system around the optical axis with respect to the first optical system to switch between the first position and the second position.
6. The projection lens according to claim 5, wherein the reversing unit includes a click mechanism for fixing the second optical system at the first position and the second position.
When the second optical system is not arranged at any of the first position and the second position and the sensor is in an undetected state in which the sensor is turned off, the light is blocked from blocking light from the image forming panel. The projection lens according to claim 3, further comprising a portion.
A projection lens according to any one of claims 3 to 6,
The image forming panel for displaying the image;
A light source that illuminates the image forming panel;
A housing for shifting and storing one of the image forming panel and the projection lens in a direction perpendicular to the optical axis;
In conjunction with the switching of the second optical system to the first position or the second position, the direction of the projected image on the projection surface is adjusted at the first position and the second position based on the signal of the sensor. A projector comprising: an image display reversing unit that reverses the image.
When the second optical system is not arranged at any of the first position and the second position and the sensor is in an undetected state in which the sensor is turned off, the light is blocked from blocking light from the image forming panel. The projector according to claim 8, wherein a projector is provided between the projection lens and the image forming panel.
A projection lens according to claim 7;
The image forming panel for displaying the image;
A light source that illuminates the image forming panel;
A housing for shifting and storing one of the image forming panel and the projection lens in a direction perpendicular to the optical axis;
In conjunction with the switching of the second optical system to the first position or the second position, the direction of the projected image on the projection surface is adjusted at the first position and the second position based on the signal of the sensor. A projector comprising: an image display reversing unit that reverses the image.
The projector according to any one of claims 8 to 10, wherein the projection lens is detachably attached to the casing.